Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Bulgarian
сойка
←
Bulgarian
со́а
(affix)
←
Bulgarian
-ка
(affix)
←
Proto-Slavic
*sojьka
(inherited)